Reporter: Clare Brady

They're small -- half the size of match head -- but when termites team together they can destroy houses and hope. Sisters Marion Jarvis and Margaret Rowarth know how relentless termites can be.

It was Margaret's dream to grow old in her late parent's home but the house has been completely gutted by termites. Now it'll be burnt to the ground. "It's devastating to be honest - devastating", Margaret said.

They blame these two gum trees outside the property. Both gums are protected by the local council in the country Victorian town of Euroa. While their home goes, the council says it's hands-off the trees that house the termites. "Two very sound grey box trees, they've been assessed -- they're healthy trees", said Cr. David Westphalen.

He says he's bound by council rules -- cold comfort to Marion and Margaret. For almost two decades, the sisters and their late parents have paid thousands of dollars for the trees to be treated for termites -- a fight they've lost.

In Queensland, New South Wales and Victoria, one in four homes is hit by termites. "We estimate the damage to houses each year is about $950 million -- greater than floods and bushfires put together", said Robert Caulfield from building advisory body, Archicentre. And he has a warning. "We're entering the danger termite season. This is the time of the year when termites are getting active, when weather is warming up. First sign is flying ants inside the home -- this is termites on their reproductive cycle", he said.

For the latest weapon against termites, pest controller, Brendan Stanford uses an ultra sound device that seeks them out. There's a bigger breed in the wings, double the size and ten times more destructive. "The giant northern termite -- they can eat through a home in a matter of days, they've already reached Rockhampton and as Australia gets warmer, they're expected to creep south putting homes at risk", said Associate Professor Barry Nuller of the University of Queensland. "To protect your home, have your annual inspections, try and keep the moisture down also. If you have a plumbing leak for instance, try and get it fixed straight away because a lot of the moisture can create termite activity. Trees and stumps -- get everything removed", he added. But sometimes, even despite the best of efforts, this army, with millions of sets of teeth, wins the war.

For further information on Archicentre call: 1300 134 513.